It is known to remove oil from water on which it is floating using devices called oleophilic skimmers. These oleophilic skimmers are rotating discs usually provided in sets, mounted on axes parallel to the liquid surface such that each disc is partially immersed in the liquid. As each disc rotates, the surfaces of the immersed portion thereof become coated with oil which is then carried away from the bulk liquid as the disc continues to rotate. The oil is removed from each disc at a point further along the rotation path by a scraper or blade associated with the disc and is then channelled to the oil outlet or tank.